When well fluid is produced from a subterranean formation, the fluid typically contains particulates, or “sand.” The production of sand from the well must be controlled in order to extend the life of the well. One technique to accomplish this involves routing the well fluid through a downhole filter formed from gravel that surrounds a sandscreen. More specifically, the sandscreen typically is a cylindrical mesh that is inserted into and is generally concentric with the borehole of the well where well fluid is produced. Gravel is packed in the annular area between the formation and the sandscreen. The well fluid being produced passes through the gravel, enters the sandscreen and is communicated uphole via tubing that is connected to the sandscreen.
The gravel that surrounds the sandscreen typically is introduced into the well via a gravel packing operation. In a conventional gravel packing operation, the gravel is communicated downhole via a slurry, which is a mixture of fluid and gravel. A gravel packing system in the well directs the slurry around the sandscreen so that when the fluid in the slurry disperses, gravel remains around the sandscreen.
In a conventional gravel packing operation, fluid may prematurely leave the slurry. When this occurs, a bridge forms in the slurry flow path, and this bridge forms a barrier that prevents slurry that is upstream of the bridge from being communicated downhole. Thus, the bridge disrupts and possibly prevents the application of gravel around some parts of the sandscreen.
For purposes of circumventing any possible bridges, a system for packing a well may include alternate path transport tubes, tubes that provide, as their names imply, alternative paths for communicating the slurry down into the well. In effect, the transport tubes serve as shunts in that should a bridge form, one of the transport tubes serves to bypass the bridge to permit slurry to be introduced into the well beyond the bridge. Examples are shown in U.S. Pat. No. 7,407,007, incorporated herein by reference.
It is typically desirable to protect the transport tubes and sand screens with a shroud to prevent damage while running in hole or during operation. Often, the shroud is installed as two separate pieces that may meet at or near the longitudinal center of the screen joint. Also present at or near the center of the screen joints is a bracket that is installed to secure the transport tubes. When installed, it may be necessary to have a clearance between the shroud and the screen. That clearance may preferably be about 0.20 inches. However, when these two pieces are installed consistent alignment of the two pieces is often difficult or impossible due to the play that exists between the outer diameter of the middle bracket and the inner diameter of the shrouds necessary to introduce the desired clearance.
It would be desirable to create a solution to cure or alleviate the play between the middle bracket and the shroud.